Training collars for dogs are typically choke chain collars or pinch collars, both of which constrict around a dog's neck when tension is applied from the leash. These devices are commonly made of chain, but may include a fabric, webbing, or leather portion. Another type of training device utilizes a loop of rope, fabric, webbing or leather that is made smaller as tension is applied from the leash end of the device. This style of device may be as simple as a rope with a loop at the end. The other end is inserted through the loop to make a larger loop that slips freely, which is placed around the neck of the animal. A major problem with all of these training devices is that they work by applying a constricting, or choking, action on the animal's neck.
One design which eliminates the unrestricted choking action of the training device is made by using a separate loop to cause the collar to constrict, with a strap or chain of a fixed length attached by loops to the constricting loop. This style of device still operates based on a constricting or choking action, but the extent of constriction around the neck is limited due to the fixed-length portion of the device. However, when a separate chain loop is used to cause the collar to tighten it is possible for a dog to get a paw caught in that loop which is difficult to remove and may pose an injury risk to the animal.
Another limitation of these prior art devices is that they are not appropriate to be worn by the animal full time due to the risk of choking injury or death. This means that these devices must be put on the animal just before they are used, and removed immediately after use. Besides the inconvenience of applying and removing the training device, this may give the animal being trained the cue that it must obey training commands while the device is being worn, but not once it is removed.